What people either don't understand or are intentionally ignoring is that Iran does not need a navy in order to shut down the straight. Launch some sunburns at tankers passing through the straight and sink them, that would greatly hamper shipping through there. The Russians gave Iran the S-400 anti aircraft defense systems along with sunburns while at the same time claiming a delay in shipment. The west has no answer for these anti-ship missiles, They fly under radar height and are supersonic. They are designed to sink warships quickly. What good is our navy if it's sitting at the bottom of the Persian Gulf?